Fallacy Finder
Bad arguments, in plain English. Search by name, or describe what happened: “they changed what I said” finds the straw man.
63 fallacies
Ad hominemRelevance Attacking the person making the argument instead of the argument.
How to spot itDoes the reply say anything about the claim itself, or only about the speaker's character, job or past?
Example“Why believe his review of the restaurant? He's never cooked anything in his life.”
How to answer itAgree that the person is beside the point, then return to the claim and ask what is wrong with it.
Topicspolitics, media, law, debate
Appeal to motiveRelevance Dismissing a claim because of what the speaker stands to gain from it.
How to spot itIs the reply about why they say it, and not about whether it is true?
Example“Of course the baker says bread is healthy. He sells it.”
How to answer itMotive is a reason to check the evidence. It doesn't make the claim false.
Topicsmoney, politics, media, science
BulverismRelevance Assuming someone is wrong, then explaining why they hold the mistaken view.
How to spot itDoes the reply explain away a belief before showing it is false?
Example“You only think that because of how you were raised.”
How to answer itSay that why you believe something is separate from whether it is true, and ask for the argument.
Topicspsychology, politics, religion, debate
False balanceRelevance Giving two positions equal space when the evidence strongly favours one.
How to spot itIs a well-supported view presented as half of a fair fight with a weak one?
Example“We invited one doctor and one person who dislikes doctors, to be fair.”
How to answer itFairness means weighing evidence, not splitting the time.
Topicsmedia, science, politics, health
False dilemmaRelevance Presenting two options as if they were the only ones.
How to spot itLook for “either… or” and “with us or against us”. Is there a third choice being hidden?
Example“You're either for this plan or you want the company to fail.”
How to answer itName the options that were left out.
Topicspolitics, morality, work
False equivalenceRelevance Treating two things as equal because they share one feature.
How to spot itDo the two things only look alike on one point, with a big difference in size or kind?
Example“A parking ticket and a bank robbery are both breaking the law, so they're the same.”
How to answer itName the difference in size, kind or cost that the comparison ignores.
Topicspolitics, media, law, morality
Genetic fallacyRelevance Judging an idea by where it came from, not by whether it is true.
How to spot itIs the idea being rejected or accepted because of its source and not its content?
Example“That diet can't work. It was invented by a marketing company.”
How to answer itWhere an idea started may be a reason to check it carefully. It is not a reason to reject it. Ask about the evidence.
Topicshistory, science, media
Guilt by associationRelevance Rejecting an idea because someone disliked also holds it.
How to spot itIs the argument that “a bad person agrees with this”, and nothing more?
Example“You like that band, and so did a villain, so you must share his views.”
How to answer itA bad person can be right about some things. Ask whether the claim is true.
Topicspolitics, history, media
Middle groundRelevance Assuming the truth must lie halfway between two positions.
How to spot itIs “somewhere in the middle” offered without checking either side?
Example“One says the bridge is safe and one says it will collapse, so it's half safe.”
How to answer itTruth isn't an average. Look at the evidence for each side.
Topicspolitics, law, science, negotiation
Motte and baileyRelevance Defending a bold claim by falling back to a modest one when challenged, then returning to the bold one.
How to spot itDoes the claim shrink under pressure and grow back later?
Example“Everyone should give up cars!” “I just meant people should walk more sometimes.” (Later:) “As I said, give up cars.”
How to answer itAsk which claim they are defending, and hold them to it.
Topicspolitics, debate, media
Moving the goalpostsRelevance Changing what would count as proof after the earlier standard has been met.
How to spot itWas the test agreed before the evidence arrived? Did it quietly get harder afterwards?
Example“Show me one study.” (You do.) “Fine, but I meant a large one.” (You do.) “But not from that country.”
How to answer itAsk up front what evidence would change their mind, and say it back to them.
Topicsscience, politics, law, debate
Poisoning the wellRelevance Discrediting a source in advance, so that nothing it says will be believed.
How to spot itIs someone being warned off before they've said anything, rather than answered after?
Example“Before you read his article, remember who pays him.”
How to answer itAsk what is wrong with the claims themselves, once you've read them.
Topicsmedia, politics, debate
Red herringRelevance Slipping in a different topic to lead the discussion away from the point.
How to spot itIs the reply answering the question you asked, or a more comfortable one nearby?
Example“Why was the report late?” “Honestly, people forget how hard this team works.”
How to answer itAcknowledge the new point briefly, then ask your original question again.
Topicspolitics, law, media, debate
Special pleadingRelevance Applying a rule to everyone else but exempting yourself without a good reason.
How to spot itIs there a rule that quietly stops applying to the person who stated it?
Example“Rules matter, but my case is different.”
How to answer itAsk what makes this case different, and whether that would also excuse others.
Topicslaw, morality, work, politics
Straw manRelevance Attacking a weaker version of what someone said, instead of what they actually said.
How to spot itCompare the reply with the original claim. If the reply is easier to knock down than what was said, someone has swapped it.
Example“I think we should spend less on the new stadium.” “So you want the city to fall apart and never have any fun?”
How to answer itRestate your actual claim in one sentence and ask them to respond to that.
Topicspolitics, media, relationships, everyday, debate
Tu quoqueRelevance Dismissing a criticism by pointing out that the critic does the same thing.
How to spot itDoes the reply show the criticism is wrong, or only that the critic is no better?
Example“You say I should stop being late, but you were late last week.”
How to answer itGrant the point if it's fair, then say that it doesn't change whether the original criticism is right.
Topicspolitics, morality, relationships
Appeal to authorityAuthority and crowds Treating someone's title or fame as proof, instead of looking at their reasons.
How to spot itIs the speaker's status doing the work of an argument? Is the expert speaking outside their field?
Example“A famous actor says this supplement works, so it does.”
How to answer itExperts are worth listening to. Ask for the reasoning and the evidence, and whether other experts agree.
Topicsscience, health, media, religion
Appeal to common senseAuthority and crowds Treating something as obvious so it doesn't need an argument.
How to spot itIs “it's just common sense” offered in place of reasons?
Example“It's obvious. Anyone can see it.”
How to answer itMany true things aren't obvious, and some obvious things are false. Ask why.
Topicsscience, philosophy, politics, debate
Appeal to natureAuthority and crowds Claiming something is good because it is natural, or bad because it isn't.
How to spot itIs “natural” standing in for “safe” or “healthy”?
Example“It's a natural remedy, so it can't hurt you.”
How to answer itPlenty of natural things are harmful and plenty of made things are helpful. Ask about the evidence for this one.
Topicshealth, science, food
Appeal to noveltyAuthority and crowds Claiming something is better because it is new.
How to spot itIs “new” or “modern” the whole case?
Example“It's the latest version, so it must be an improvement.”
How to answer itAsk what it does better than the old one, and how you'd know.
Topicstechnology, business, progress, marketing
Appeal to traditionAuthority and crowds Claiming something is right because it has long been done.
How to spot itIs age being offered as the only reason?
Example“We've always held the meeting on Fridays, so Friday is the best day.”
How to answer itAsk what the practice achieves, and whether something would achieve it better.
Topicshistory, tradition, religion, culture, politics, past, old, customs
Appeal to wealthAuthority and crowds Treating wealth or success as proof that someone is right, or poverty as proof they are wrong.
How to spot itIs the person's bank balance used in place of an answer?
Example“He owns three boats, so his investing advice must be right.”
How to answer itSuccess can come from luck or other skills. Ask for the reasoning and the record.
Topicsmoney, business, politics
BandwagonAuthority and crowds Claiming something is true or good because many people believe it or do it.
How to spot itIs popularity being offered as the only reason?
Example“Millions of people use it, so it must be good for you.”
How to answer itAsk what the evidence is, apart from the headcount. Many people have been wrong together before.
Topicsmedia, technology, money, everyday, marketing
Chronological snobberyAuthority and crowds Dismissing an idea because it is old, or assuming that newer ideas must be better.
How to spot itIs the date of an idea doing the work of an argument against it?
Example“That was written two thousand years ago, so it can't apply today.”
How to answer itAsk whether the reasoning holds up. Old ideas are sometimes right and new ones sometimes wrong.
Topicshistory, philosophy, science, religion, culture
Broken window fallacyCause and effect Counting what is spent and gained, and ignoring what that money would otherwise have done.
How to spot itWhenever someone says an event or a subsidy “creates jobs”, ask what the same money would have done if it hadn't been used that way.
Example“The storm was terrible, but it created work for every roofer in town.” (The townspeople now have less to spend on everything else.)
How to answer itCount both sides: what was gained, and what was lost or never happened. Frédéric Bastiat set this out in his 1850 essay “That Which Is Seen, and That Which Is Not Seen”.
Topicseconomics, money, politics, history, government
Correlation is not causationCause and effect Assuming that two things which move together must have a cause-and-effect link.
How to spot itCould a third factor drive both? Could the cause run the other way?
Example“Ice cream sales and drownings rise together, so ice cream causes drowning.” (Both rise in summer.)
How to answer itAsk what else could explain the link, and whether anyone tested it.
Topicsstatistics, science, health
Post hocCause and effect Assuming that because one thing followed another, the first caused the second.
How to spot itIs timing the only link between the two events?
Example“I wore my lucky socks and we won. The socks work.”
How to answer itLook for other causes, and ask whether there is a mechanism that connects the two.
Topicshealth, science, superstition
Regression to the meanCause and effect Crediting a treatment for a change that would have happened anyway, since extreme results tend to return to normal.
How to spot itWas the change measured after an unusually bad or good time?
Example“I only called the doctor on my worst day, and I felt better the next day. The call helped.”
How to answer itAsk what would have happened with no treatment at all.
Topicshealth, statistics, sport, science
Reverse causationCause and effect Assuming A causes B when B actually causes A.
How to spot itCould the effect be the cause?
Example“Happy people have more friends, so friends make you happy.” (Perhaps happy people find it easier to make friends.)
How to answer itAsk which came first, and how you'd test the other direction.
Topicsstatistics, health, science, psychology
Single causeCause and effect Blaming one factor for something that has several causes.
How to spot itIs a complicated outcome being explained by one thing?
Example“The company failed because of its logo.”
How to answer itAsk what else contributed, and how much each factor mattered.
Topicshistory, economics, politics
Slippery slopeCause and effect Claiming that one small step will inevitably lead to a terrible outcome, without showing each link.
How to spot itIs each step in the chain argued, or only assumed?
Example“If we let them have a casual Friday, soon nobody will wear anything to work.”
How to answer itAsk for the evidence for each link. A real slope has reasons at every step.
Topicspolitics, law, morality
Appeal to consequencesEmotion Judging whether something is true by whether its results are pleasant.
How to spot itIs “it would be terrible if this were true” used as a reason to think it isn't?
Example“There can't be a shortage. Think of the panic if there were.”
How to answer itWhether something is true doesn't depend on whether we like the consequences.
Topicspolitics, science, health, economics
Appeal to emotionEmotion Using feeling, such as pity, anger or guilt, in place of reasons.
How to spot itIs the feeling replacing the evidence? Would the argument still stand with the emotion removed?
Example“If you cared about the team, you'd vote for my plan.”
How to answer itTake the feeling seriously, then ask what it shows about whether the claim is true.
Topicspolitics, media, charity
Appeal to fearEmotion Trying to win by frightening people about what happens if they disagree.
How to spot itIs the danger real and shown, or only suggested?
Example“Without this insurance, one accident could ruin your family.”
How to answer itAsk how likely the danger is, what the evidence is, and whether the proposal would actually prevent it.
Topicspolitics, media, health, money
Appeal to flatteryEmotion Praising someone in order to win their agreement.
How to spot itDoes the compliment come attached to a request or a conclusion?
Example“A smart person like you will obviously agree.”
How to answer itThank them, then judge the claim on its merits.
Topicsmarketing, work, relationships, politics
Appeal to ridiculeEmotion Making an idea look silly instead of showing it is wrong.
How to spot itIs a joke, a nickname or an eye-roll doing the work of an argument?
Example“Oh, so the moon is made of cheese now?”
How to answer itLaugh if it's funny, then ask what is actually wrong with the idea.
Topicsmedia, politics, debate, comedy, satire
Wishful thinkingEmotion Believing something because you want it to be true.
How to spot itIs hope being treated as evidence?
Example“It'll definitely work out. It has to.”
How to answer itAsk what would be different if you were wrong, and check that.
Topicsmoney, relationships, work, health
Anecdotal evidenceEvidence and logic Using one person's story as if it settled a general question.
How to spot itIs a single case, or a handful, being treated as the pattern?
Example“My uncle smoked every day and lived to ninety, so smoking is fine.”
How to answer itA story can be real and still unrepresentative. Ask how common the outcome is.
Topicshealth, media
Argument from incredulityEvidence and logic Concluding something is false because you can't imagine how it could be true.
How to spot itIs “I can't see how” offered as the reason?
Example“I don't see how a computer could write a sonnet, so it can't.”
How to answer itYour limits aren't the world's. Ask what the evidence says.
Topicsscience, technology, religion, history
Argument from silenceEvidence and logic Taking the lack of a record or mention as proof something didn't happen.
How to spot itWould the thing have been recorded? Does the record even survive?
Example“The diary doesn't mention rain, so it didn't rain.”
How to answer itAsk whether the source would have mentioned it, and whether anything has been lost.
Topicshistory, science, law
Base rate fallacyEvidence and logic Judging a probability from a striking detail while ignoring how common the thing is overall.
How to spot itHow common is this outcome before you add the new information?
Example“The test is 95% accurate and I tested positive, so I almost certainly have it.” (If the condition is very rare, most positives are false.)
How to answer itStart from how common it is, then adjust.
Topicsstatistics, health, science, law
Begging the questionEvidence and logic Using the conclusion as one of the reasons for the conclusion.
How to spot itDoes the argument only work if you already accept what it is trying to prove?
Example“The book is true because it says so, and it wouldn't lie.”
How to answer itAsk for a reason that doesn't assume the conclusion.
Topicsreligion, philosophy, law
Cherry-pickingEvidence and logic Showing only the evidence that supports your case, and leaving out the rest.
How to spot itAsk what the whole picture looks like. What was left out, and why?
Example“Sales rose 20% in March!” (They fell in the other eleven months.)
How to answer itAsk for the full data, or the full period, not just the favourable part.
Topicsstatistics, media, science, economics, history
Conjunction fallacyEvidence and logic Thinking two things together are more likely than one of them alone.
How to spot itHas an extra detail made a story sound more likely?
Example“She's likely a librarian who also plays the flute, more than just a librarian.”
How to answer itAdding details can only make something less likely, never more.
Topicsstatistics, psychology
Continuum fallacyEvidence and logic Rejecting a distinction because there is no sharp line between the two ends.
How to spot itIs “where exactly is the line?” offered as proof there's no difference?
Example“There's no exact hour when day becomes night, so there's no difference.”
How to answer itBlurry edges don't erase real differences at the extremes.
Topicsphilosophy, law, science, language
Ecological fallacyEvidence and logic Drawing conclusions about individuals from data about their group.
How to spot itIs a statistic about a region or group used to describe a person?
Example“That town has high incomes, so this resident must be wealthy.”
How to answer itA group average says little about any one member.
Topicsstatistics, politics, science, culture
EquivocationEvidence and logic Using a word in two different senses within one argument.
How to spot itDoes a key word mean the same thing at the start and at the end?
Example“Laws are made by lawmakers, and a law of nature is a law, so nature has a lawmaker.”
How to answer itPin down the word's meaning first, then check whether the argument still works.
Topicsphilosophy, law, religion, language
Fallacy fallacyEvidence and logic Concluding a claim is false because the argument for it was bad.
How to spot itIs a faulty argument being taken as proof that the conclusion is wrong?
Example“Your reasoning was sloppy, so you must be wrong.”
How to answer itA bad argument leaves the claim unsupported, not disproved.
Topicsdebate, philosophy
Fallacy of compositionEvidence and logic Assuming that what is true of the parts is true of the whole.
How to spot itIs a property of each piece being applied to the group?
Example“Each brick is light, so the wall is light.”
How to answer itCheck the whole separately. Wholes can behave differently from parts.
Topicseconomics, statistics, science, politics
Fallacy of divisionEvidence and logic Assuming that what is true of the whole is true of each part.
How to spot itIs a property of the group being pinned on each member?
Example“The team is excellent, so every player is excellent.”
How to answer itCheck each part separately.
Topicsstatistics, politics, sport, work
Gambler's fallacyEvidence and logic Believing that past random results change the odds of the next one.
How to spot itAre the events independent, such as coin tosses, but treated as if they balance out?
Example“It's come up red six times, so black is due.”
How to answer itIndependent events have no memory. Each toss is a fresh one.
Topicsmoney, statistics, gambling
Hasty generalizationEvidence and logic Drawing a broad conclusion from too few or unrepresentative examples.
How to spot itHow many cases is the conclusion based on, and how were they picked?
Example“I met two rude people from that city. Everyone there is rude.”
How to answer itAsk how big and how fair the sample was.
Topicspolitics, culture, prejudice
Is-oughtEvidence and logic Moving from how things are to how they should be without saying why.
How to spot itDoes the argument slide from a fact to a duty with no moral premise in between?
Example“People have always fought wars, so we ought to.”
How to answer itAsk for the moral premise that links the fact to the “should”.
Topicsmorality, philosophy, politics, history
Loaded questionEvidence and logic Asking a question that has a disputed assumption built into it.
How to spot itCan the question be answered without accepting something you never agreed to?
Example“Have you stopped wasting company money?”
How to answer itPoint out the assumption, and answer that before the question.
Topicslaw, media, politics
No true ScotsmanEvidence and logic Protecting a claim by redefining the group so counterexamples don't count.
How to spot itDid the definition change right after someone gave a counterexample?
Example“No honest person would cheat on taxes.” “My neighbour did.” “Then he wasn't really honest.”
How to answer itAsk for the definition before looking at examples.
Topicspolitics, religion, morality
Proof by assertionEvidence and logic Repeating a claim, more firmly each time, instead of supporting it.
How to spot itHas the claim been said three times but never argued?
Example“It's true. It's simply true. I don't know how many times I have to say it.”
How to answer itAsk for one reason that doesn't repeat the claim.
Topicspolitics, debate, religion, marketing
ReificationEvidence and logic Treating an abstraction as if it were a real thing that acts.
How to spot itIs “the market”, “society” or “history” doing something as if it were a person?
Example“History will punish them.”
How to answer itAsk which people are acting, and what they actually did.
Topicseconomics, politics, history, philosophy
Shifting the burden of proofEvidence and logic Claiming something is true because it hasn't been disproved, and asking others to disprove it.
How to spot itWhoever makes the claim owes the evidence. Is the other side being asked to prove a negative?
Example“There's a dragon in my garage. Prove there isn't.”
How to answer itSay that the claim needs support first. Absence of disproof isn't evidence.
Topicsreligion, science, law
Survivorship biasEvidence and logic Judging by the examples that survived and forgetting those that didn't.
How to spot itWho is missing from the story? What happened to the failures?
Example“Famous founders dropped out of college, so dropping out leads to success.”
How to answer itAsk how many tried the same thing and didn't make it.
Topicsmoney, business, history, statistics
Texas sharpshooterEvidence and logic Finding a pattern in the data after the fact, and treating it as if it had been predicted.
How to spot itWas the claim chosen before looking at the data, or after?
Example“Look, every disaster happened within a year of a comet.” (After searching a century of disasters for comets.)
How to answer itAsk what was predicted in advance, and test it on new data.
Topicsstatistics, science, history, media
Nirvana fallacyMoney and decisions Rejecting a good option because it isn't perfect.
How to spot itIs a real option being compared with an imaginary perfect one?
Example“Seat belts don't prevent every death, so why bother?”
How to answer itCompare the real options with each other, not with perfection.
Topicspolitics, health, law, technology, economics
Sunk costMoney and decisions Continuing something because of what you've already put into it, not because of what it will return.
How to spot itIs “we've already spent so much” the reason to carry on?
Example“We've spent three years on this, so we can't stop now.”
How to answer itPast costs are gone either way. Ask only what the next step costs and returns.
Topicsmoney, business, work, relationships
Zero-sum thinkingMoney and decisions Assuming that one person's gain must be another's loss, as if the total were fixed.
How to spot itIs the economy, the number of jobs or the amount of wealth treated like a fixed cake?
Example“Every job a machine does is a job a person loses for good.”
How to answer itAsk whether the total can grow, and what the freed resources do next.
Topicseconomics, money, politics, work, technology
No match. Try describing what happened, such as “they ignored my point”, or clear a category.
These are short guides, not rulings. Whether an argument commits a fallacy often depends on context, and the examples are invented. Spotted a mistake or a missing fallacy? Get in touch.